Ad hoc wireless distribution service

About: Ad hoc wireless distribution service is a research topic. Over the lifetime, 17734 publications have been published within this topic receiving 488205 citations.

How to achieve a connected ad hoc network with homogeneous range assignment: an analytical study with consideration of border effects

Abstract: The paper presents an analytical investigation of the connectivity of wireless ad hoc networks with randomly uniformly distributed nodes and homogeneous transmission range assignment The probability that a network is connected depends on the number of nodes, n, per area, A, and their transmission ranges, r/sub 0/. We derive an analytical expression that enables the determination of critical (r/sub 0/, n)-pairs that achieve, with high probability, a connected network in an area A. As opposed to prior analytical work on this topic (see Bettstetter, C., Proc. ACM Symp. on Mobile Ad Hoc Networks and Comp.-MobiHoc, 2002), we now consider border effects, which have significant impact on the obtained results. Furthermore, we calculate the expected node degree and the probability that the network has no isolated node. All three results are of practical value in simulation and system design of ad hoc and wireless sensor networks. While the paper considers a circular system area, the methods can also be applied to other shapes.

System for enabling mobile coverage extension and peer-to-peer communications in an ad hoc network and method of operation therefor

Abstract: A method for enabling mobile coverage extension and peer-to-peer communications in an ad hoc network is provided. The method includes communicating at least one message among the plurality of nodes, wherein the at least one message comprises: an ad hoc zone, wherein the ad hoc zone comprises at least one channel selected from a group of channels comprising: at least one synchronization channel for synchronizing out of coverage nodes, at least one access channel for peer-to-peer communications, and at least one ad hoc relay data/traffic channel for exchanging data during data sessions between one or more nodes.

Replica allocation in ad hoc networks with periodic data update

Abstract: Recent advances in computer and wireless communication technologies have led to an increasing interest in ad hoc networks which are temporarily constructed by only mobile hosts. In ad hoc networks, since mobile hosts move freely, disconnections occur frequently, and this causes frequent network division. Consequently, data accessibility in ad hoc networks is lower than that in the conventional fixed networks. Assuming an environment where each data item is periodically updated, we propose three replica allocation methods to improve data accessibility by replicating data items on mobile hosts. In these three methods, we take into account the access frequency from mobile hosts to each data item, the status of the network connection, and the time remaining until each item is updated next. We also show the results of simulation experiments regarding the performance evaluation of our proposed methods.

SWANS- Scalable Wireless Ad hoc Network Simulator User Guide

Abstract: Wireless networking research is fundamentally dependent upon simulation. Analytically quantifying the performance and complex behavior of even simple protocols on a large scale is often imprecise. On the other hand, performing actual experiments is onerous: acquiring hundreds of devices, managing their software and configuration, controlling a distributed experiment and aggregating the data, possibly moving the devices around, finding the physical space for such an experiment, isolating it from interference and generally ensuring ceteris paribus, are but some of the difficulties that make empirical endeavors daunting. At a minimum, one would like to simulate networks of many thousands of nodes. However, even though a few parallel discrete event simulation environments have been shown to scale to networks of beyond 10 nodes, slow sequential network simulators remain the norm [8]. In particular, most published ad hoc network results are based on simulations of few nodes only (usually fewer than 500 nodes), for a short duration, and over a small geographical area. Larger simulations usually compromise on simulation detail. For example, some existing simulators simulate only at the packet level without considering the effects of signal interference. Others reduce the complexity of the simulation by curtailing the simulation duration, reducing the node density, or restricting mobility. SWANS is a Scalable Wireless Ad hoc Network Simulator built atop the JiST platform, a general-purpose discrete event simulation engine. SWANS was created primarily because existing wireless network simulation tools are not sufficient for current research needs. SWANS also serves as a validation of the virtual machine-based approach to simulator construction.

A reliable multicast algorithm for mobile ad hoc networks

Abstract: A reliable multicast algorithm, called RMA, for mobile ad hoc networks is presented that is based on a new cost criterion, called link lifetime, for determining the optimal path between a pair of nodes. The algorithm has the characteristics of using an undirected graph for its routing operations rather than a fixed structure like a tree or a mesh. Previously proposed routing metrics for mobile ad hoc networks were designed for use in wired environments, where link stability is not a concern. We propose a new metric, called the lifetime, which is more appropriate for mobile ad hoc networks. The lifetime metric is dependent on the predicted future life of the link under consideration. We developed a simulator for the mobile ad hoc networks, which is portable and scalable to a large number of nodes. Using the simulator, we carried out a simulation study to analyze the effectiveness of the routing metrics and the performance of the proposed reliable multicast algorithm. The simulation results show that the lifetime metric helps achieve better performance in mobile ad hoc environments than the hop count metric.